Experimental investigation of the evolution of controlled perturbations in a longitudinal vortex generated in a boundary layer on a flat plate at a Mach number $\mathrm{M}=2$

Using the results of experimental studies, a comparison is made of the space-time distributions of the amplitude of controlled pulsations in the linear and weakly nonlinear phases of the development of a wave train in homogeneous and inhomogeneous boundary layers on a flat plate at a Mach number $\mathrm{M}=2$. (The inhomogeneity of the flow is caused by a longitudinal stationary perturbation generated by a pair of weak shock waves. Controlled perturbations were generated locally from the surface at a fixed power of the high-frequency glow discharge inside the model.) It is established that the inhomogeneity of the flow changes the mechanism of interaction of subharmonic perturbations. It is shown that in the center of the wave train there is a violation of the spatial synchronism of pulsations of subharmonic frequency.